Beware of the Pine Processionary Caterpillar: A Hidden Danger for Pets in Spain

Feb 8

2 min read

As the weather starts warming up in Spain, a silent but serious danger emerges for our pets: the pine processionary caterpillar (Thaumetopoea pityocampa). These caterpillars are found in pine trees, where they form large nests that look like candyfloss or white silk. But don’t be fooled by their seemingly harmless appearance—these creatures can cause severe allergic reactions in dogs and cats, sometimes with devastating consequences.

Why Are These Caterpillars Dangerous?

Pine processionary caterpillars are covered in tiny, toxic hairs that act like microscopic needles. These hairs contain a protein that can trigger intense allergic reactions upon contact. The risk is especially high when these caterpillars leave their nests and crawl in long “trains” across the ground, often attracting the curiosity of pets.

If a dog or cat sniffs, licks, or bites a caterpillar, these toxic hairs can get into their mouth, tongue, and digestive system, leading to severe symptoms and tissue damage. The reaction can be so extreme that, in worst-case scenarios, parts of the tongue may become necrotic and fall off within days. In rare cases, exposure to the caterpillar’s toxins can even be fatal.

Signs Your Pet May Have Been Exposed

If your pet has come into contact with a processionary caterpillar, you may notice:

Excessive drooling
Pawing at the mouth
Swelling of the tongue or lips
Vomiting or diarrhea
Difficulty breathing
Lethargy or signs of distress

What to Do If Your Pet Encounters a Caterpillar

Time is crucial when dealing with a pine processionary caterpillar reaction. Here’s what you should do:

Flush the mouth immediately: Use plenty of clean water (or saline solution if available) to rinse your pet’s mouth, removing as many hairs as possible. Do not rub the area, as this can cause the hairs to break and release more toxins.
Seek veterinary help immediately: Your vet will administer strong anti-inflammatory medication, such as antihistamines and corticosteroids, to control the allergic reaction and prevent further damage.
Avoid handling the caterpillars: Their hairs can also cause painful reactions in humans, leading to skin irritation, rashes, and even respiratory issues.

How to Protect Your Pet

To reduce the risk of exposure:

Avoid walking near pine trees during early spring, when the caterpillars are most active.
Keep your dog on a leash in areas where processionary caterpillars are common.
Regularly check your surroundings for nests in pine trees or caterpillar trails on the ground.
Inform fellow pet owners about this danger so they can also take precautions.

Final Thoughts

Most pets recover well if they receive prompt treatment, but prevention is always better than cure. If you live in or visit Spain, especially in wooded or pine-rich areas, be extra cautious during the caterpillar season. Stay aware, act fast, and protect your furry friend from this hidden but serious threat.